Wireless Local Area Networks (WLANs) commonly use access points for transmitting data between the network and mobile stations such as laptops, personal digital assistance (PDAs), cellular phones, etc. However, a WLAN system that uses the IEEE 802.11b protocol affords only three sets of access points for three distinct frequencies because that protocol allows only three non-overlapping channels or three different carrier frequencies that all access points in a system may use. Consequently, a first set of access points use a first frequency. A second set of access points use a second frequency, and a third set of access points uses a third frequency. Because access points using the same frequency may interfere with one another, to avoid interference, those access points must be placed outside the coverage range of one another. As a result, access points in the first set that uses the first frequency must be placed outside the coverage range of one another. Access points in the second set that uses the second frequency must be placed outside the coverage range of one another, and access points in the third set that uses the third frequency must be placed outside the coverage range of one another, etc.
Access points using the IEEE 802.11 protocol also have limited coverage ranges, e.g., 15 meters for the 802.11a protocol or 100 meters for the 802.11b protocol. Therefore, covering a large area requires many access points. Additionally, the more mobile stations that try to communicate with an access point, the smaller the bandwidth each mobile station can afford. In general, it is very difficult for a mobile station in a basic service set (BSS) of an access point to communicate with another mobile station in the BSS of another access point.
A WLAN system further requires an Ethernet switch that uses the IEEE 802.3 Ethernet protocol, which differs from the IEEE 802.11 wireless protocol. Therefore, mechanisms to convert data between the two protocols must be employed. Even though the Ethernet switch uses multiple physical lines for multiple channels, it cannot process data concurrently received from multiple channels or multiple mobile stations. In many situations, data sent from a source mobile station to a destination mobile station travels through an access point, through the Ethernet switch, then back through the same access point. This results in inefficiency and delays.
Networks using the CSMA/CD protocol allow only half duplex, i.e., either transmitting or receiving data at a time. Networks using the 802.11 protocol and the CSMA/CA have similar disadvantages. An access point cannot concurrently process data for multiple mobile stations. Each mobile station time-shares the same medium having the same frequency carrier.
Because of the above-mentioned deficiencies, what is needed is mechanisms to solve those deficiencies and related issues.